CN112342185B - Bioreactor process for chick embryo cell rabies virus - Google Patents
Bioreactor process for chick embryo cell rabies virus Download PDFInfo
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Abstract
The invention relates to a bioreactor process for treating chicken blastocyte rabies virus; the method is characterized in that a sheet-shaped carrier and a serum-free culture medium are utilized to culture primary chick embryo cells in a bioreactor with a fixed bed basket type stirring system, and a high-titer and high-antigen rabies virus harvesting solution is prepared by specific upper tank cell density, the inoculation amount of a CTN chick embryo cell vaccine strain-CTNCEC 25 strain (CGMCC No. 6510) and the set parameters of the bioreactor. The average virus titer is not less than 7.0lgFFU/mL, the highest virus titer can reach 8.7lgFFU/mL, the average antigen content is not less than 2.0IU/mL, the highest antigen content can reach 4.0 IU/mL, the receiving solution can reach 2-3 effective culture volumes, the labor intensity and the production cost are greatly reduced, the production efficiency is greatly improved, and a culture mode for producing rabies viruses by primary cell large-scale culture is initiated.
Description
Technical Field
The invention relates to the technical field of biological products, is applied to the production of primary chick embryo cell rabies vaccines, and particularly relates to a bioreactor process for chick embryo cell rabies viruses.
Background
Rabies (Rabies) is an ancient virulent zoonotic disease caused by Rabies virus (RABV) that affects the central nervous system and can cause severe encephalomyelitis, with mortality rates of almost 100% once it occurs. Almost all warm-blooded animals can be infected with rabies, with various mammals being their primary hosts among others. At present, no effective rabies treatment method exists, and rabies vaccine inoculation in time after exposure is the most main prevention means.
After the rabies vaccine for human beings is developed for more than 100 years, the quality and the safety of the vaccine are greatly improved from the earliest attenuated active vaccine to the avian embryo vaccine to the current cell culture vaccine and the genetic engineering vaccine in a laboratory stage. Rabies vaccines in developed countries such as europe, the united states and japan are mainly Purified Chick Embryo Cell Vaccine (PCECV) and Purified Human Diploid Cell Vaccine (PHDCV). The two vaccines have high safety and good immune protection effect, wherein PHDCV is the gold standard of human rabies vaccine determined by WHO, but the production scale is difficult to enlarge due to the characteristic of human diploid cells, so that the yield of PHDCV is seriously insufficient, the final sale price is high (the current market price is about 1500 yuan/person number, and the average price of Vero cell vaccine is about 300 yuan/person number), and the market scale is limited; the immunogenicity and safety of PCECV can be compared with PHDCV, and the PCECV is a safe and effective high-quality rabies vaccine, and the price of the PCECV on the market is about 1000 yuan per person and is also obviously higher than the price of Vero cell vaccine. In developing countries, the main rabies vaccine on the market is the Purified Vero Cell Vaccine (PVCV) with lower production cost for reasons of economic development level. Since Vero cells are an infinite cell line, have potential tumorigenic risks and DNA residue problems, and become a main obstacle to the future market share of Vero cells, currently, developed countries such as Europe and America have basically eliminated PVCV.
The rabies vaccines which are marketed in China at present mainly comprise PVCV, PCECV and PHDCV. Because the Vero cell culture process is simple, the cost is low, and the expanded culture is convenient, the PVRV becomes the masterforce of the rabies vaccine market for Chinese people, and the production enterprises are numerous and account for about 95 percent of the total amount of the batch rabies vaccine in China. However, because Vero cells are a continuous cell line with a potential carcinogenic risk, the safety of PVRV applications has been controversial. On the other hand, although HDCV is an internationally recognized gold standard product, HDCV has serious disadvantages, i.e., slow human diploid cell proliferation, too long vaccine production process, low virus propagation titer, and complex production process and low yield, so that the vaccine is high in cost, expensive and difficult to popularize in developing countries. The PCECV has better immune protection and the effect is equivalent to that of HDCV, so the PCECV is an ideal substitute vaccine for HDCV. At present, PCECV is imported from China only by GSK, no domestic manufacturer is available for production, and a certain domestic enterprise for carrying out the clinical application of PCECV adopts a cell factory production process. Although the cell factory process is stable and has small batch-to-batch difference, the cell density is low, the virus titer is low, the antigen is low, the liquid collection volume is small, the labor intensity is high, and the industrial economic benefit is low.
At present, the cell factory culture process is a primary cell matrix culture method of mature chick embryo cells and the like. The Chinese patent publication No. CN108452298A discloses a process for producing yellow fever attenuated live vaccine by SPF chick embryo cells, which has the defects of low cell culture density, low virus titer, high labor intensity and the like. Chinese patent publication No. CN1390604 discloses a method for large-scale continuous production of virus vaccines, which adopts a Celligen Plus bioreactor of a fixed bed basket stirring system, takes polyester slices Fibra-Cel Disks as a carrier, has the scale of only 5.0-7.5L, and is not suitable for large-scale production of rabies vaccines.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, provides a bioreactor process for producing rabies viruses by using chick embryo cells, and provides a method for producing rabies viruses by using a fixed bed bioreactor to culture primary chick embryo cells.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a method for producing rabies virus by culturing primary chick embryo cells in a fixed bed bioreactor comprises the following steps:
(1) Preparing primary chick embryo cells: taking Specific pathogen-free (SPF) chick embryos of 9-11 days old, shearing, digesting with trypsin, centrifuging to remove digestion liquid, and preparing single chick embryo cell suspension after cell precipitates are resuspended in a serum-free culture medium. Specifically, the chicken embryo is obtained by incubating SPF fertilized eggs for 9-11 days.
(2) Cell seeding into bioreactor: in a bioreactor with a fixed bed basket agitator systemInoculating the primary chick embryo cell suspension prepared in the step (1) by taking an NBS flaky carrier as a carrier and a serum-free culture medium as a culture medium, wherein the inoculation density is 2.3-3.6 x 10 6 Per mL;
(3) Inoculation of rabies virus CTNCEC25 strain: inoculating primary chick embryo cells into a bioreactor for 0-8 h, inoculating a working seed batch of virus seeds into the bioreactor according to the infection amount of MOI = 0.005-0.05 FFU/cell, and uniformly mixing the virus seeds with the primary chick embryo cells to enable the virus to infect the cells;
(4) Adjusting bioreactor control parameters: the temperature is 33-37 ℃, the pH value is 7.3-7.7, the stirring speed is less than or equal to 90rpm, the dissolved oxygen is 30-80 percent, and virus liquid is cultured and harvested;
(5) Harvesting virus solutions in batches: after virus inoculation, culturing until the glucose content is less than 3.0g/L, the virus titer is more than or equal to 6.5lgFFU/mL, and the antigen content is more than or equal to 1.0IU/mL, and harvesting virus supernatant; the whole volume harvest or half volume harvest is adopted for 3-5 times. Typically, the virus supernatant is harvested when cultured for about 72h, 96h, 120h, 144h or 168h after virus inoculation. The virus harvest can adopt whole volume harvest or half volume harvest and proper harvest time according to the glucose content (less than 3.0 g/L), the virus titer (more than or equal to 6.5 lgFFU/mL) and the antigen content (more than or equal to 1.0 IU/mL). Generally, the culture medium can be harvested for 3 to 5 times, and the harvesting volume can reach 2 to 3 effective culture volumes. Wherein, the virus titer detection adopts a cell immunofluorescence method, the antigen detection adopts an ELISA method, and the glucose content detection adopts a biochemical detector.
Further, the concentration of trypsin used in the above-described protocol was 0.25%.
Furthermore, in the technical scheme, the method comprises the following steps. The serum-free culture medium is a mixed culture medium, namely preferably a mixed culture medium added with 0.1-0.5% of human serum albumin and 100-2500 ng/mL of dextran sodium sulfate on the basis of the serum-free culture medium; generally, the serum-free medium is a commercially available serum-free medium mainly used for culturing primary chick embryo cells and rabies viruses, and a commercially available serum-free medium with a product number of H5E5L7 from Shanghai culture Biotechnology GmbH is adopted in the embodiment of the invention. Preferably, the mixed culture medium is a serum-free culture medium added with 0.3-0.5% human albumin and 100-200 ng/mL dextran sodium sulfate.
Furthermore, in the above technical scheme, the seeding density of the primary chick embryo cells is preferably 2.6-3.0 x 10 6 one/mL.
Further, the sheet-like carrier used in the above technical solution is similar to that provided by NBS corporation in usa or other manufacturers, and the preferable amount of the sheet-like carrier is 15 to 30g/L, and the more preferable amount of the sheet-like carrier is 20 to 25g/L.
Further, in the above-mentioned embodiment, it is more preferable that the amount of infection is 0.005 to 0.01FFU per cell,
further, the rabies virus CTNCEC25 strain in the technical scheme is obtained in patent number ZL 201410132141.9. The virus cultured in the inoculation reactor in examples 1 to 6 was CTNCEC25 strain working seed batch virus seed.
Further, in the above-mentioned embodiment, the temperature in the step (4) is more preferably 35 to 37 ℃, the pH is more preferably 7.4 to 7.6, the stirring rate is more preferably 60 to 90rpm, and the dissolved oxygen is more preferably 50 to 70%.
Furthermore, in the technical scheme, the average virus titer of the virus harvesting solution is more than 7.0LgFFU/mL, the antigen content is more than 2.0IU/mL, and the volume of the harvesting solution is more than or equal to 2.
At present, due to the improvement of national standards, rabies vaccines are produced by adopting a bioreactor basically so that all indexes reach the standard of Chinese pharmacopoeia. The variety of bioreactors and carriers in the market is various, wherein the fixed bed bioreactor of the American NBS company has good quality, high technical level and wide application, and the corresponding sheet carriers produced by the American NBS company are used in a matching way. However, in the process of a large number of experimental researches, the invention discovers that the effect of producing the rabies virus by using the bioreactor with the basket type stirring system and matching with the corresponding polyester fiber flaky carrier to culture the primary chick embryo cells can also reach the ideal requirement. The average virus titer is not less than 7.0lgFFU/mL, the average antigen content is not less than 2.0IU/mL, and the liquid yield can reach 2-3 effective working volumes, which can not be reached by using a stirred tank bioreactor or other carriers (such as Cytodex1 microcarriers, polyester fiber sheet carriers and the like) under the same culture conditions.
Compared with the prior production process and patents of the rabies vaccine, the main unique characteristics of the invention are as follows:
1. the invention adopts primary chick embryo cells as the cells for culturing the rabies virus.
Primary chick embryo cells are a class of avian primary cells that are in widespread use. Compared with other primary cells, the cell is relatively easy to obtain, has strong proliferation capacity and adaptability, good tolerance and stable properties, is not easy to transform and is an important cell matrix for vaccine production. Compared with Vero cells, the safety is higher. According to the report, a relatively mature process for culturing primary chick embryo cells in a large scale in China is a cell factory process, and the method has the defects of low cell culture density, low virus titer, high labor intensity and the like.
2. The rabies virus strain used in the invention is CTNCEC25 strain.
The production of vaccine strains is the key to produce high quality vaccines. The vaccine strains applied in China mainly comprise aGz strain, CTN-1 strain and Flury strain. The CTN-1 strain used in the invention is subjected to continuous subculture of primary chick embryo cells to obtain a CTN chick embryo cell vaccine strain (see patent ZL201410132141.9 for details). Sequence comparison shows that compared with the aGz strain, the CTN-1 strain and the Flury strain currently used in China, the CTNCEC25 strain has higher homology with epidemic strains separated in China, so that the CTNCEC25 strain, which is a primary chick embryo cell vaccine strain based on the CTN-1 strain, is more suitable for preventing and treating rabies in China.
3. The invention can be applied to a CELLIGEN310 type 14L bioreactor of the United states NBS company or a bioreactor which is produced by domestic manufacturers, has the same structure and principle as the NBS and is provided with a basket type stirring system;
the bioreactor of the basket type stirring system simulates the static growth environmental condition of cells, provides an environment similar to that of spinner flask culture for the cells, has the advantages of small shearing force, high culture density and the like, and can be suitable for various animal cells, insect cells, plant cells and the like; batch type, fed-batch type, perfusion type and other culture modes can be adopted; determining the cell concentration by detecting the glucose content of the culture medium; the batch culture method has the main advantages of short culture period, simple operation, high utilization rate of nutrient substances in the culture medium and higher antigen expression concentration than other modes.
In the existing cell factory technology, each layer of chick embryo cells prepared by inoculating 4 SPF chick embryos needs to be inoculated, the single virus liquid yield is small and is about 50 mL/embryo, but the virus liquid yield is 130-200 mL/embryo, so that the method is more suitable for large-scale production.
The invention is not limited to the use of NBS corporation CELLIGEN model 310 14L bioreactors. The method has great benefits for later-stage production process amplification, and different companies can purchase corresponding pilot-scale test and commercial production equipment according to own cost budgets without worrying about process troubles brought by equipment of different manufacturers.
The invention can be applied to polyester fiber sheet carriers produced by NBS company or similar sheet carriers produced by other companies;
the present invention is not limited to the use of polyester fiber sheet-like supports manufactured by NBS corporation. That is, the carrier material and structure are the same or similar to NBS carrier, and the quality meets the requirements of relevant regulations, so the method can be used for producing primary chick embryo cell rabies vaccine. The method also has great benefits for later-stage production process amplification, different companies can purchase corresponding pilot-scale test and commercial production consumables according to own cost budgets, and the trouble in the process caused by carrier replacement is avoided.
The culture medium adopted by the invention is a serum-free culture medium.
At present, the culture solution used for culturing chick embryo cell prophase in the process of producing vaccines in China is basic culture medium such as M199, DMEM and the like, and proper bovine serum is added. The serum-free culture medium is produced by Shanghai culture Biotechnology Limited, and is added with components such as cell adherence promoting factors, amino acids and the like which accord with Chinese pharmacopoeia according to the growth characteristics of primary cells, so that the serum-free culture medium is not only beneficial to cell adherence and proliferation, but also does not contain any animal-derived protein or bovine serum, has higher product safety, and accords with the requirements of the Chinese pharmacopoeia on the safety of biological products.
The invention adopts a cell immunofluorescence method to determine the virus titer, an ELISA method to detect the antigen content, and a biochemical detector to monitor the glucose content. A large number of early experimental researches show that the method can accurately and quickly evaluate the virus harvest liquid so as to accelerate the treatment of subsequent processes.
The invention realizes the large-scale and high-density culture of rabies virus produced by primary chick embryo cells, the obtained virus harvest liquid drop size is not lower than 7.0lgFFU/mL, the antigen content is not lower than 2.0IU/mL on average, the liquid yield can reach 2-3 effective working volumes, and the labor cost and the production cost are also greatly reduced. According to preliminary statistics, each time 1L of virus harvest liquid is produced, about 5 layers of cell factories and 20 chick embryos are needed to be used in the cell factory process, and the production cost is about 800 yuan; while the fixed bed bioreactor only needs 6.5-10g of sheet-shaped carriers and 5-8 chick embryos, and the production cost is about 210-320 yuan. In contrast, the process of the invention is more suitable for the industrial production of the primary cell rabies vaccine. In addition, the virus culture is carried out by adopting a serum-free culture medium without animal-derived additives, so that the safety is higher.
Drawings
FIG. 1 growth distribution of primary chick embryo cells in a sheet-like support, wherein, A-blank sheet-like support; B. c, D, E, F, G-sheet support cultured for 5 days in sequence from examples 1-6; the adhesion of the chick embryo cells of examples 1-6 to the sheet-like support can be seen from the figure, which illustrates that the chick embryo cells can grow well on the sheet-like support.
FIG. 2 is a growth curve of a bioreactor for culturing primary chick embryo cells; the glucose consumption curves for the whole course of cell growth of examples 1-6 can be seen from the graphs, illustrating that the cells rapidly enter the logarithmic growth phase in the bioreactor, and are cultured for about 44h to reach the peak of proliferation and maintained for about 96 h.
FIG. 3 example 1-3 viral titer profiles of rabies virus illustrating the optimization of the fine particlesCell inoculation density of 2.3-3.6X 10 6 Culturing the virus to 96-120 h, wherein the average virus titer of the virus harvest liquid is more than 7.0LgFFU/mL.
FIG. 4 antigen expression profiles of rabies viruses of examples 1-3, illustrating cell seeding density optimization to 2.3-3.6X 10 6 Culturing the virus to 96-120 h, wherein the average antigen content of the virus harvest liquid is more than 2.0IU/mL, and the volume of the harvest liquid is more than or equal to 2.
FIG. 5 is a graph showing the change in viral titer of rabies virus in examples 4-5, demonstrating that by optimizing the agitation rate to ≦ 90rpm, the average viral titer of the viral harvest still achieved 7.0LgFFU/mL.
FIG. 6 is an antigen expression profile of rabies virus in examples 4-5, which illustrates that by optimizing the stirring rate to 90rpm or less, the average diseased antigen content of the virus harvest is greater than 2.0IU/mL, which results in 3 harvest volumes.
FIG. 7 is a graph showing the variation of viral titer and antigen expression of rabies virus in example 6, showing that when the virus culture scale is enlarged to 30L, the titer, antigen content level and harvest volume of the virus harvest are all equivalent to 14L, the average viral titer is > 7.0LgFFU/mL, the antigen content is > 2.0IU/mL, and the volume of the harvest is > 2.
Detailed Description
The technical scheme of the invention will be clearly and completely described by combining the specific examples and the comparative examples.
Cell: preparing primary chick embryo cells by adopting SPF (specific pathogen free) chick embryos of 9-11 days old;
and (3) poisoning seeds: CTNCEC25 strain with the titer more than or equal to 7.0lgFFU/mL;
a bioreactor: NBS Celligen model 310 14L or DOE-40L bioreactors with fixed bed basket agitator systems;
carrier: NBS polyester fiber sheet-shaped carrier or domestic polyester fiber sheet-shaped carrier;
cell factory: NUNC,10 layers/piece, total 6320cm 2 Area of culture.
Culture medium: the serum-free medium with the product number of H5E5L7 of Shanghai culture Biotechnology GmbH is mainly used for culturing chicken embryo cells and rabies viruses, and can also be directly used in the following example 1 of the invention. However, since the chick embryo cells of the present invention are primary cells prepared from chick embryos that have grown for 9-11 days, in the following examples of the present invention, in order to study how to improve the quality of the primary cells, it was verified by comparative experiments that the growth state of the cultured cells is significantly improved, the number of clumped cells is reduced by 80%, and the cell activity is increased by about 2 times, in the culture medium mixture prepared by adding 0.5% human serum albumin and 100ng/ml dextran sodium sulfate to the serum-free medium.
Example 1
(1) Selecting 9-11 days old chick embryos which have normal development and clear visible blood vessels and activity. Soaking in 0.2% (m/v) benzalkonium bromide solution for 5-10 min, and spraying 75% (v/v) alcohol for burning and sterilizing. The embryos are removed aseptically and placed in dishes containing PBS solution (pH 7.4). Removing the head of the chick embryo, putting the chick embryo into a sterilized wide-mouth bottle, and shearing the chick embryo into a size of 1-5 mm by using sterile scissors 3 Adding 0.25% (m/v) trypsin solution preheated to 37 ℃ into the tissue block according to the amount of 5-8 mL of each chick embryo, and placing the tissue block in a water bath tank at 37 ℃ for digestion for 15-30 minutes. Centrifuging at 1500-3000 rpm for 8-10 min at room temperature, removing supernatant, and resuspending the precipitate in serum-free culture medium to obtain single chick embryo cell suspension. 2mL of cell suspension was added to 16mL of purified water and mixed well, and the cell number was calculated by the following formula using a turbidimeter for reading:
cell density (pieces/mL) =2.4 × 10 4 X turbidity x 8
(2) The bioreactor was assembled and the pellet and PBS solution (pH 7.4) autoclaved in advance were filled in an amount of about 20g/L into a fixed basket and autoclaved at 121 ℃ for at least 120 minutes. The PBS solution was discarded, and a medium (serum-free medium containing 0.5% human serum albumin and 100ng/ml dextran sulfate) was added thereto, and the mixture was incubated at pH7.4, a temperature of 37 ℃ and a stirring speed of 70rpm for at least 24 hours or more. Adding the prepared primary chick embryo cell suspension in the step (1), and respectively adjusting the inoculation density to be 2.3 multiplied by 10 6 seed/Ml, culture volume 10L. Adjusting pH to 7.4, temperature to 37 deg.C, stirring speed to 70rpm, and dissolved oxygen to 70%。
(3) The cells are inoculated into a bioreactor for 4-6 hours, and the batch virus seeds of the rabies virus CTNCEC25 strain working seeds are inoculated according to the quantity of MOI =0.01 FFU/cell.
(4) And (3) discharging all the cell maintenance liquid in the bioreactor 48 hours after cell inoculation, adding fresh culture medium with the same volume, and continuing to culture. The culture parameters of the bioreactor were adjusted to 35 deg.C, pH7.6, dissolved oxygen value 70%, and stirring speed 70rpm.
(5) After about 72 hours of culture, virus fluid was harvested at 50% or 100% working volume and then supplemented with an equal volume of fresh medium (serum-free medium containing 0.5% human serum albumin and 100ng/ml dextran sulfate) and the culture was continued. The culture parameters of the bioreactor are adjusted to 35 ℃, pH7.6, dissolved oxygen value 70%, and stirring speed 70rpm. Thereafter, harvesting is performed at 50% or 100% active working volume every approximately 20-24 hours until glucose consumption is < 0.5g/L.
Example 2
The difference from example 1 is that the cell seeding density when the bioreactor is used for culturing cells is 3.0X 10 6 one/mL.
Example 3
The difference from example 1 is that the seeding density of the cells when the bioreactor is used for culturing the cells is 3.6X 10 6 one/mL.
Example 4
The difference from example 1 is that the cell seeding density when the bioreactor is used for culturing cells is 3.3X 10 6 pieces/mL, the stirring speed in the tank was 90rpm.
Example 5
The difference from example 1 is that the cell seeding density when the bioreactor is used for culturing cells is 3.3X 10 6 pieces/mL, the stirring speed in the tank was 120rpm.
Example 6
The difference from example 1 is that the cell seeding density when the bioreactor is used for culturing cells is 3.3X 10 6 one/mL, culture volume in pot 30L.
Comparative example 1
A cell factory process is used.
The difference from example 1 is that single chick embryo cell suspensions were prepared and cell suspension densities were measured as in step "(1)" of example 1 using cell growth medium (M199 medium containing 10% (v/v) bovine serum, pH 7.4);
the difference from example 1 is that the virus seeds are added to the cell suspension at 0.01MOI, mixed homogeneously and added to the cell suspension at 1.0X 10 6 one/mL was seeded into a 10-layer cell factory, 150 mL/layer. After culturing in a 37 ℃ carbon dioxide incubator for 48 hours, the cells were replaced with a cell maintenance solution (M199 medium containing 0.3% (v/v) human serum albumin, pH 7.6), and cultured at 34 ℃ for 120 hours to harvest the whole supernatant in the cell factory.
TABLE 1 Virus titer, antigen content and harvest volume for rabies virus culture in bioreactor and cell factory
As can be seen from the results of examples 1-3 and comparative example 1 of Table 1, the results of the present invention, which are optimized in terms of cell seeding density, are: the cell inoculation density is 2.3-3.6 multiplied by 10 6 Cell-consumed glucose levels peak at 72h in culture at individual/mL, with a virus titer > 7.0. At the moment, virus liquid is harvested in a full volume or a half volume, the average virus titer of the virus harvest liquid is larger than 7.0LgFFU/mL, the antigen content is larger than 2.0IU/mL, and the liquid harvesting volume is larger than or equal to 2. The antigen content of the virus harvest solution obtained by the invention is more than 2.5 times of that of the cell factory process of the group of the comparative example 1, and the harvest volume is more 2-3 times, which shows that under the appropriate cell inoculation density, the invention can effectively promote the proliferation of the chick embryo cells and the virus propagation, and completely achieve the expected effect of culturing primary chick embryo cells to produce rabies viruses.
As can be seen from the results of examples 4-5 of Table 1, the results of the present invention in optimizing the stirring rate are: when the agitation rate increased above 90rpm, the cell-depleted glucose level began to drop significantly; when the virus is propagated to the titer which is more than or equal to 7.0LgFFU/mL, the virus is harvested, the average virus titer of the virus harvest liquid with the stirring speed of 90rpm can still reach 7.0LgFFU/mL, the antigen content is more than 2.0IU/mL, and the volume of 3 harvest liquids is 3; while 3 volumes could be harvested at a stirring rate of 120rpm, the average viral titer of the viral harvest was less than 7.0LgFFU/mL and the antigen content was less than 2.0IU/mL. The reason is that the excessively high stirring rate can cause the shearing force in the bioreactor to obviously damage cells, so that the cell growth and the virus proliferation are not facilitated, and the culture effect is reduced.
As can be seen from the results of example 6 of Table 1, the results of the present invention on the scale-up of culture were: the titer, antigen content level and harvest volume of the virus harvest solution are all equivalent to 14L by adopting a 40L bioreactor to culture cells and viruses, which shows that the invention can better protect the cells from the influence of mechanical force and environmental change in the linear amplification process, keeps better substance and heat transfer effect and is more suitable for large-scale production.
In conclusion, the virus harvest liquid with high titer and high antigen can be produced by culturing the chick embryo cells by adopting the method, and the productivity of the virus harvest liquid is far higher than that of a cell factory technology; the linear amplification to 40L still keeps the advantages of low shearing force, good transfer effect, high cell growth density and the like, and is more suitable for large-scale production and application. Meanwhile, the high-quality virus harvest liquid lays a solid foundation for subsequent purification and final preparation of rabies vaccine.
The above-described embodiments are intended to illustrate rather than to limit the invention, and any modifications and variations of the present invention are possible within the spirit and scope of the appended claims.
Claims (2)
1. A bioreactor process for preparing chick embryo rabies virus is characterized in that: the method comprises the following steps:
(1) Preparing primary chick embryo cells: taking SPF chick embryos of 9-11 days old, shearing, digesting with trypsin, centrifuging to remove digestive juice, and preparing a single chick embryo cell suspension after cell precipitation is resuspended in a serum-free culture medium; the trypsin concentration used was 0.25%;
(2) Cell seeding into bioreactor: in a bioreactor with a fixed bed basket agitator system in the form of sheetsTaking a carrier as a carrier and a serum-free culture medium as a culture medium, inoculating the primary chick embryo cell suspension prepared in the step (1) with the inoculation density of 2.3-3.0 x 10 6 Per mL; 0.5% human serum albumin and 100ng/ml dextran sodium sulfate are also added into the serum-free culture medium; the usage amount of the flaky carrier is 20g/L;
(3) Inoculation of rabies virus CTNCEC25 strain: inoculating primary chick embryo cells into a bioreactor for 4-6 h, inoculating the working seed batch virus seeds into the bioreactor according to the infection amount of MOI =0.01 FFU/cell, and uniformly mixing the virus seeds with the primary chick embryo cells to enable the virus to infect the cells;
(4) Adjusting bioreactor control parameters: culturing and harvesting virus liquid at 35 ℃, pH value of 7.6, stirring speed of 70-90 rpm and dissolved oxygen of 70%;
(5) Harvesting virus solutions in batches: after virus inoculation, culturing until the glucose content is less than 3.0g/L, the virus titer is more than or equal to 7.0lgFFU/mL, and the antigen content is more than or equal to 2.0IU/mL, and harvesting virus supernatant; the whole volume harvest or half volume harvest is adopted for 3-5 times, and the liquid collection volume is more than or equal to 2.
2. The process according to claim 1, characterized in that: the sheet-shaped carrier adopted in the step (2) is a sheet-shaped carrier of NBS company in America.
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| US4320115A (en) * | 1977-01-26 | 1982-03-16 | Gist-Brocades N.V. | Rabies virus vaccine |
| CN102240400A (en) * | 2011-05-25 | 2011-11-16 | 长春生物制品研究所 | Method for producing rabies vaccine by applying bioreactor and sheet carrier |
| CN103865888A (en) * | 2014-04-03 | 2014-06-18 | 深圳市卫光生物制品股份有限公司 | Adapting method of rabies virus (RV) CTN-1 strain to primary chicken embryo fibroblast |
| CN108452298A (en) * | 2017-02-17 | 2018-08-28 | 无锡鑫连鑫生物医药科技有限公司 | A kind of technique producing yellow fever attenuated live vaccine with SPF chick-embryo cells |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4320115A (en) * | 1977-01-26 | 1982-03-16 | Gist-Brocades N.V. | Rabies virus vaccine |
| CN102240400A (en) * | 2011-05-25 | 2011-11-16 | 长春生物制品研究所 | Method for producing rabies vaccine by applying bioreactor and sheet carrier |
| CN103865888A (en) * | 2014-04-03 | 2014-06-18 | 深圳市卫光生物制品股份有限公司 | Adapting method of rabies virus (RV) CTN-1 strain to primary chicken embryo fibroblast |
| CN108452298A (en) * | 2017-02-17 | 2018-08-28 | 无锡鑫连鑫生物医药科技有限公司 | A kind of technique producing yellow fever attenuated live vaccine with SPF chick-embryo cells |
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